Long hours spent staring at your computer screen, phone or tablet increases your exposure to blue light – a key component of the visible light spectrum. Blue light, which has the shortest wavelength in the spectrum, is emitted by these common digital devices as well as TVs and fluorescent/LED lights.
According to a survey carried out by the Ernst & Young consultancy, people in Singapore spend 12 hours and 42 minutes per day on average on digital devices with the maximum time – 3 hours and 12 minutes – spent on the mobile phone.
This excessive exposure to blue light has raised serious questions about its impact on the eyes.
Experts, however, assure that there is no scientific evidence that blue light from digital devices harms your eyes. They say that the discomfort you experience after prolonged periods of staring at your computer screen or phone is most likely caused by eye strain and dry eyes since you tend to blink less when you look at a screen.
But, while normal exposure to blue light – sunlight is a natural source of blue light – is not harmful, excessive exposure may affect your circadian rhythm or sleep and wake cycle. Blue light can increase alertness and disrupt sleep since it may delay the release of melatonin, the main sleep-promoting hormone.
Can blue light blocking glasses protect your eyes?
Blue light blocking glasses come with lenses that have a special pigment or coating to block out some of the blue light. Experts claim that there is a lack of evidence about the effectiveness of these glasses to protect your eyes from strain, improve visual performance or improve sleep quality.
“The Academy does not recommend any special eyewear for computer use,” says the American Academy of Ophthalmology, and adds that taking such preventive measures against blue light even though there is no evidence of damage could be more harmful than the blue light itself.
Instead of using blue light blocking glasses, follow these tips to protect your eyes:
Sit at a distance of about two feet from your computer screen and gaze slightly downwards
Use the “20-20-20” rule – every 20 minutes, shift your eyes to look at an object at least 20 feet away for at least 20 seconds
If your eyes feel dry, use moisturising eye drops
Remove digital devices from your bedroom and stop using them a couple of hours before you sleep at night
Have an annual eye exam to monitor your eye health